The present invention relates to an automated installation for punching and cleaning nozzles of converters used in non-ferrous metallurgy.
In the present state of the art there are numerous designs of these installations. The most similar to the presented invention being in U.S. Pat. No. 1,219,963, relating to an installation for punching converter tuyeres directed to maintaining them in operating condition for ensuring free passage. The installation consists of two combined cylinders, whereas the piston rod of the top cylinder drives the cross rod with the heads accommodating the punching rod for every second tuyere mounted thereon and the piston rod of the bottom cylinder drives the punching rod for the remaining tuyeres. The described installation is suited to a simultaneous punching of half a number of tuyeres being built in one converter during one working cycle. The remaining tuyeres are punched during the next working cycle of the machine.
The above mentioned design makes use of:
(a) a small working speed of the punching rod within the punching zone and the required use of a cylinder of very great power in order to obtain the forces necessary for a simultaneous piercing of all tuyeres; and
(b) a considerable length of the punching unit rendering impossible this to be used in contemporary converters.
Furthermore, the above mentioned installation is suited to converters with a vertical layout which are no longer used in contemporary non-ferrous metallurgy.
In an installation according to the British Patent No. 632,602 there have been used one to three punching units moving along the converter tuyeres, each of them consisting of two cylinders, whereas the bottom cylinder drives the top cylinder mounted on suitable springs having a piston rod provided with a punching rod situated at the end of the rod. The punching units are moved along a separate unit by means of a line power cylinder and pull rods on suitable rails, whereas the driving system used enables alignment of the punching unit with the individual tuyeres and punching of the tuyeres. The punching units either move along the long stationary rails of the converter or the rails themselves are moved along a circular track with respect to the converter, thus rendering possible the converter tuyeres to be pierced at various converter positions.
The design mentioned and described above has the following features:
(a) the top cylinder with its piston rod having a large bearing surface passes through a ball closure of the tuyere head and in this very place the piston rod bearing surface often becomes damaged and, consequently, the top cylinder becomes loose and is unserviceable after a short time of operation;
(b) the punching rod being an extension of the piston rod is rigidly connected with this piston rod. In practice, the tuyeres are not built in one line and the introduction of the piercing rod requires an appropriate positioning of the top cylinder mounted on suitable springs in order to enable the necessary displacement of the cylinder. This design is disadvantageous since a rapid introduction of the piercing pin into the tuyere is accompanied with a rapid resetting of the cylinder; considerable weight of the cylinder and the large forces of inertia causing rapid displacement, produces destructive bending forces as well as an accelerated abrasive action;
(c) the unit for moving the punching unit along a circular track requires ample free space and makes difficult access to the tuyeres necessary for maintenance.
Installation according to the Polish Patent No. 90,615 consists of a set of several cylinders combined in series, wherein the individual feeds and speeds are added algebraically. The set of cylinders moves on guideways rendering it possible to align the piercing unit with the individual tuyeres. The punching rod connected with the extreme piston rod of the cylinder is introduced into the tuyere. The whole installation is either fastened to the converter or may move on a separate unit over a circular track, thus rendering it possible for the tuyeres to be pierced at various positions of converter.
The operation of the installation is completely automated and does not require additional manipulations. The design discussed herein above employs a punching unit of considerable length thus rendering it impossible for the application of the unit to converters built too close the bearing structure of the converter house.
The automated installation for punching and cleaning of converter tuyeres according to the present invention is fitted with a travel unit (car) fastened either to the converter housing or to a separate unit rendering it possible to displace the punching unit with respect to the tuyeres and, consequently, allowing the punching operation to take place at a stationary or revolved converter.
The punching unit is provided with suitable working tools either in the form of a punching rod slidable along the axis of the tuyeres or a slidable rotary drill mounted in the supporting guide introducing the punching end of the punching rod or drill into the tuyere. The opposite end of the punching rod or drill is secured in a car mounted on the rail and moved along it by means of the driving unit.